refactor: remove Ollama integration and unused AI configuration

- Remove src/models/ollama_client.py, embeddings.py, embeddings_ollama.py
- Remove model aliases and AI config from settings (both config.py files)
- Update health endpoints to only check database connectivity
- Update tests to reflect database-only health checks
- Update README, .env.example, and OIDC docstrings

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,22 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.10.4] - 2026-01-07
+
+### Removed
+
+- **Ollama integration removed** - AI inference is no longer handled by this API
+  - Removed `src/models/ollama_client.py` and all Ollama-related configuration
+  - Removed `src/models/embeddings.py` and `src/models/embeddings_ollama.py`
+  - Removed model aliases and AI configuration from settings
+  - Health endpoints no longer check Ollama status
+  - Tests updated to reflect database-only health checks
+
+### Changed
+
+- Health check `/health/full` now only checks database connectivity
+- Diagnostics endpoint simplified (removed Ollama component info)
+
 ## [1.10.3] - 2026-01-07
 
 ### Fixed